Natural Gas air conditioning???

[JDuke]

Can't seem to find much information on line about gas powered air conditioning

Did see they can have efficiency rates up to 27 Seer which is much higher than electric systems.

Someone else mentioned using the heat from motor to heat water for hot water.

But can't find much more information.
Anybody have one or any experience with them?

[Rob Young]

That's what my parents had in their house in SW Kansas for about 40 years.  Two zones, inside units were HUGE.  Each about the size of two telephone booths (as long as we are talking about "old" equipment).  No idea if modern units are smaller and more efficient.  No outside condensers, everything was in the basement.  Heat and cool and air handlers in same units.

Equipment had lifetime support from local gas company.  At least for 40 years and then as I understand it, the last guy on the company payroll that could deal with the old systems retired.  So they switched to a more conventional system with two outside condensers.  New system is MUCH more efficient.  And they got back a lot of storage space in the basement mechanical room.

Interestingly, the old system (I think) relied entirely on city water for the cooling portion.  I remember as a kid, in the summer, Mom would have us move hoses around the yard and when the AC kicked on, the cooling water was diverted after it had been warmed up and used to spot water problem areas of the lawn.  Or could be diverted down the drain.  The outside spigots are still in place on the house, just not connected to anything inside.

[Phil Thien]

That's what my parents had in their house in SW Kansas for about 40 years.  Two zones, inside units were HUGE.  Each about the size of two telephone booths (as long as we are talking about "old" equipment).  No idea if modern units are smaller and more efficient.  No outside condensers, everything was in the basement.  Heat and cool and air handlers in same units.

Equipment had lifetime support from local gas company.  At least for 40 years and then as I understand it, the last guy on the company payroll that could deal with the old systems retired.  So they switched to a more conventional system with two outside condensers.  New system is MUCH more efficient.  And they got back a lot of storage space in the basement mechanical room.

Interestingly, the old system (I think) relied entirely on city water for the cooling portion.  I remember as a kid, in the summer, Mom would have us move hoses around the yard and when the AC kicked on, the cooling water was diverted after it had been warmed up and used to spot water problem areas of the lawn.  Or could be diverted down the drain.  The outside spigots are still in place on the house, just not connected to anything inside.

What you're describing is a city water-based chiller, I think.  I don't think there are any natural gas engines involved.  The system takes advantage of the cool city water temperature.

My shop had such a handler installed and yeah, it was big.  It had been converted to a Freon-based system sometime ago.

I believe the OP is looking for a system that uses a natural gas "engine" to operate a condenser-based refrigerant system.

[Rob Young]

Nope. Natural Gas.  Water instead of "freon".

Sometimes known as an absorption unit.

[bottd]

There are low pressure absorption chillers out there but as far as I know they are large commercial units.  They burn the natural gas, but could use any heat source,  to control the amount of heat in the solution which is a mixture of water and Lithium Bromide. Different principles then a compressor system, your not varying refrigerant pressures to achieve the cooling.

[Phil Thien]

Nope. Natural Gas.  Water instead of "freon".

Sometimes known as an absorption unit.

Oh. I was under the impression that low-pressure absorption units were sealed, that there wasn't a constant flow of water entering/leaving the system. When you said the unit was kicking water out constantly, I figured it wasn't such a system.

But what do I know?

[Rob Young]

Constant flow when calling for "cold".  Could be diverted to dedicated spigots to water trees/lawn or left to flow into sanitary sewer.

[Phil Thien]

Constant flow when calling for "cold".  Could be diverted to dedicated spigots to water trees/lawn or left to flow into sanitary sewer.

So then the constantly running water was likely sorta warm/hot? Because the heat had to be leaving somewhere (these units were entirely inside, nothing outside).

I don't know why, I'd sorta like to know more about those monsters.

The one in the back of my shop was about the size of a large refrigerator. It had been converted to Freon long before I got there.

BUT, one of the shops in the same building was still running their unit as recently as 2000-2002 or so. I know because I got a massive water bill and I was told the florist was running a water chiller.

I thought the units simply took advantage of the temp. differential between city water, and the atmospheric temp. Everything I read about heat pumps using water also used ammonia, and I'd have been surprised they'd allow that to discharge into the sanitary sewer even if most of the ammonia had boiled off.

[Rob Young]

Yes warm water.  No ammonia in discharge.  That loop is closed.

[Phil Thien]

Yes warm water.  No ammonia in discharge.  That loop is closed.

Well thanks for explaining that old system to me.

I always wondered how it worked.

I know it was expensive to run, at the end. Any savings from using NG was completed flushed down the drain with all that water usage. Water even on a great lake has gotten so expensive as treatment costs have increased. That, and the local gov'ts have figured out a million additional fees they can tack onto water usage.